This is a classic practical test question at Vietnamese agencies. Recruiters want to see that candidates understand 'multi-platform' does not mean posting the same content in 5 places.
Good signals: TikTok - POV or 'nghe này' hook + trending audio; Facebook - 3-5 paragraph storytelling + comment CTA; Instagram - 7-10 slide carousel or Reels under 60 seconds; Zalo OA - trustworthy, concise tone with a clear link-out because Zalo's audience skews older and is action-oriented; YouTube Shorts - strong 3-second hook + endscreen CTA back to long-form. Bonus points if the candidate mentions staggered posting schedules to avoid cannibalizing reach and leveraging cross-promotion.